In the present work a report on a series of measurements at church bells is given. Examinations of the acoustical behaviour by means of EDP place the first main focus. The partial construction and above all the timbre of bells is measured; especially it is shown, how one can appraise bell sound by means of sound analysis at the computer, a method that is completely unorthodox in the bell tidings and practically doesn't find any application. Examinations of the constructions of bells (bell shape) place the next main focus. It is shown on the one hand, how bell shapes has an effect on their acoustical behaviour, on the other hand methods, with which one can determine qualities of bell shapes, are demonstrated here. These methods facilitate to explore the development of the bell shapes as well as the operations of former bell-casters of the Gothic, renaissance and the baroque much more profoundly than it is possible up to now. Further examinations occupy themselves with the different bell metals. It is not only shown as the respective material qualities settle generally on the acoustical behaviour of bells, another exact discussion of all materials which are used for bell casting (bronze, special bronze, brass, steel, casting iron and zinc alloys) takes place. Finally bell-fittings (clappers, headstocks) and their influence on the acoustical behaviour of bells, but also aspects of tower acoustics are reported.